func IsCoinBase

Description

IsCoinBase determines whether or not a transaction is a coinbase. A coinbase
is a special transaction created by miners that has no inputs. This is
represented in the block chain by a transaction with a single input that has
a previous output transaction index set to the maximum value along with a
zero hash.

This function only differs from IsCoinBaseTx in that it works with a higher
level util transaction as opposed to a raw wire transaction.